Time report

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare readOnlyHint=true, which already conveys this is a safe read operation. The description adds useful behavioral detail: it returns aggregated hours, includes billable vs total hours, and billable amounts only when permitted. This goes beyond the annotation without contradicting it.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences with no wasted words. The first sentence front-loads the core function and options; the second gives a natural-language example. Every phrase earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Although there is no output schema, the description tells the user what the report contains (aggregated hours, billable/total hours, billable amounts) and how it can be grouped. This is enough for a simple reporting tool with only three parameters, though it does not specify response format or pagination, which is a minor gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema covers 100% of parameters (from, to, group_by) with clear descriptions, including enum values for group_by. The description adds only a slight restatement ('date range', 'grouped by'), which is minimal extra value over the schema, so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool aggregates hours over a date range with grouping options (clients, projects, tasks, team members), and the title 'Time report' reinforces this. It is distinct from siblings like list_time_entries (detailed entries vs aggregated summary) and log_time (write vs read).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides a concrete use case ('how many hours did we spend on X this month?') and implies it is for reporting/aggregation rather than listing individual entries or logging time. However, it does not explicitly name alternatives or state when not to use this tool, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.